Originally Posted by mousitsas
Interesting thoughts....but why do you say that the snorkel restricts the airbox? The inlet snorkel surface area is clearly larger than each individual carb inlet. Also, the 990R can happily put down 110+bhp with an identical airbox-snorkel.
Also, what problems do you expect if the H2W base jetting (plus larger mains) is used with a CPR filter?
From lots of dyno time, the snorkle restricts airflow into the box. Simply taking it off makes a huge difference in top end, this after
upsizing mains. In stock condition, the first thing to run out are the mains. Factory mains are still lean even with the snorkle on. I assume the 990R makes its higher top hp numbers from either/ or both more fuel flow through the injectors or higher rev limit, greater displacement...dunno. I have a 950. Simply put, an airbox equipped 950 benefits from a bigger main, its smaller fueling ability being the top end restriction in stock form, a 950 without an airbox benefits far more, as the next restriction caused by the snorkle is eliminated.
In regards to using h2w's kit intended for the prefilter, this would be a total donkey show. That system relies on greater vacuum and less atomization. The airjets will be way off, really way off, and the mains beyond dangerously small and lean. I'd not be at all surprised to see a seized motor as a result! I'm certain Ken has warned against this, repeatedly. Shifting to a tune with greater airflow, less vacuum and better atomization is totally, completely different, and require totally different settings.
Also, the stock needle has to go!